Lead-press.



No. 699,308. Patented May 6, I902.

R. F. HALL.

LEAD PRESS.

(Application filed Feb. 14, 1901.) (lo Model.) 3 Sheets-$heet I.

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Patented May 6, [902.

R. F. HALL.

LEAD PRESS.

(Application filed Feb 14, 190

3 Sheets-Sheet 2,,

(No Model.)

. I 7: far.- fiadeMaM/a/ 5% fjua r m diarmg times STATES PATENT OFFICE.

RODERIC F. HALL, OF EAST ORANGE, NEW JERSEY, ASSIGNOR TO IVESTERNELECTRIC COMPANY, OF CHICAGO, ILLINOIS, A'CORPO- RATION OF ILLINOIS.

LEAD-PRESS.

SPECIFICATION forming part of Letters Patent No. 699,308, dated May 6,1902. Application filed February 14,1901. Serial No. 47,367. (No model.)

To aZZ whom, it may concern:

Be it known that LRODERIO F. HALL, a citizen of the United States,residing at East Orange, in the county of Essex and State of willproduce straight round pipe of uniform thickness with much less powerthan is necessary with presses which use the old form of die-block.

New Jersey, have invented acertain new and In accordance with myinvention a single useful Improvement in Lead-Presses, (Caseunobstructed passage is provided, through 55 No. 2,) of which thefollowing is afull, clear, which the lead is forced into theformingconcise, and exact description. chamber, said passage openingdirectly upon My invention relates to a lead-press, and the cylindricalportion of the core-tube at the Io more particularly to apress forcovering elecrear of the die-opening. A raised tongue is tric cableswith a protective lead sheath. formed along the wall of the chamberoppo- 60 My object is to provide an improved and site the openingthrough which the lead simplified press which will require less powerenters, and the core-tube rests upon and is for its operation thansimilar machines heresustained by said tongue at this point againsttofore in use. the enormous pressure of the lead, which A lead-presswhich is well known in the art and which has been extensively employedheretofore is provided with a bridge in the die-block between thelead-cylinder and the forming chamber and passages through which thelead may flow on either side of the bridge opening into theforming-chamber on either side of the'die and core-tube. Such a bridgeis shown in the patent to Robertson, No. 346,563, granted August 3,1886. This bridge has heretofore been considered necessary to equalizethe pressure of the lead at all points around the circumference of thedie-opening in order to produce a straight round pipe of uniformthickness. A leadpress which has such a die-block requires very greatpower for its operation, and a considerable portion of this power isexpended in to the die-opening through the several passages against theresistance or obstruction caused by the bridge, which is placed directlyin the line of flow; but it has heretofore been thought impracticable toomit the bridge, since if this were done the pressure at the upper edgeof the die-opening would be much :duceda forcing the solid lead from'thelead-cylinderwould otherwise break the core-tube owing to the absence ofthe bridge before referred to. With a structure such as above outlinedthe pressure is not uniform around the dieopening, and for this reasonsuch astructure would ordinarily be impracticable, the lead pipe beingmade crooked and uneven in thickness. I have provided, however,gas-burners arranged to direct their flames upon the die-blocks andadjustable mountings for said burners, whereby the application of theheat to the lead in the forming-chamber may be varied to compensate forvariations in pressure at different points. The passage of the leadthrough the die-opening may thus be equalized at all points, so that astraight round pipe of uniform thickness may be pro- I will describe,myinvention more particular] y by reference to the accompanyingdrawings, in whichtional View on line 5 5 of Fig. 4, and Fig. 6 is aplan view of the lower half of the die-block with the die and core-tubein position.

Similar letters of reference are used to designate the same partsthroughout the several figures.

The hydraulic lead-press shown in the d rawings is of a general typewhich is well known in the art, and it consists in its elements of ahydraulic ram carrying a die-block a and the lead-holding cylinder 1) ontop ofthe dieblock and the stationary plunger or ram 0, mounted upon across-head above the open mouth of the cylinder. The ram-piston t isarranged to reciprocate vertically within the hydraulic cylinder 25, towhich water under pressure is supplied through the pipe t ram t, and thelead -holding cylinder 1) is mounted on top of the die-block in positionso that as the ram t is raised the stationary piston 0 will enter theopen mouth of said lead-cylinder and will force the solidified butplasticlead down and out through the dieopening. A steam-jacket b may beprovided for the lead-cylinder b, as shown.

The die-block of my invention is preferably formed in two halves a (L asshown, parted in the middle along thecenter line of the transverse holethrough which the cable to be sheathed is passed. The annular die d andthe tubular core-piece e are seated in this transverse hole and are heldin place by tubular bushings ff, screwed into the ends of the block. Thetwo halves of the die-block are hollowed, as shown, so that aformingchamber is produced in the interior of the die-block around theopposed ends of the die and core-tube. A single passage g is cut in theupper half of the die-bl0ck,through which the lead from the cylindermaybe forced into the forming-chamber. This hole or passage g is oblongin shape, as shown most clearly in Fig. 3, with its major diameter in aplane at right angles with the line of the tubular core. The majordiameter is preferably somewhat larger than the diameter of the coretubeand it opens into the forming-chamber directly over the core-tube somedistance to the-rear of the die-opening.

' In hollowing the lower half of the die-block to make theforming-chamber a tongue of metal 71, is left on the bottom, extendingforward to support the core-tube against the enormous downward pressureto which it will be subjected when the lead is forced down through thepassage g. This tongue h extends forward,as shown, up to the point wherethe core begins to taper to form the nose.

In the operation of the press as the lead is forced down through thepassage g it is divided by the cylindrical surface of the core and flowsdown on either side thereof, filling the forming-chamber, and as thepressure increases passes out through the annular dieopening, emergingfrom the die-block in the form of a tube or pipe 2', sheathing the cableis. It will be seen that the downward pressure of the lead from theopening 9 is sustained by the heavier cylindrical part of the Thedieblocl; a is placed on top of the core-tube and that the lead beforeit reaches the nose of the core-tube is moving in a directionlongitudinally thereof and surrounds the smaller end, so that directlateral pressure on the smaller end is avoided. With the die-block asheretofore constructed, having a bridge between the lead-chamber and thecoating chamber and passages leading into the coating-chamber on eachside of the die and core-tube, the pressure of the lead from all sidestoward the center will be substantially equalized by said bridge toforce the lead through the diet-opening and around the cable-core withthe same pressure at all points on its circumference and so to give thecable-core a coating or sheath of uniform thickness. In other words, thebridge obstructs the flow or movement of the lead at the point where ittends to flow the fastest and easiest. In the die-block of my invention,wherein the bridge is dispensed with and the resulting opposition to theflow of lead avoided, while much less power is required for theoperation of the press, yet the benefit of the equalizing effect of thebridge is not obtained. In my lead-press, therefore, to equalize the Howof lead through the die-opening I compensate for the inequality ofpressure by heating the lead in the die-block and so softening it,especially at the places where it would otherwise tend to flow theslowest. In the drawings I have shown for this purpose three gas-jets ZZ Z on each side of the dieblocl': mounted adjustably, so that they maybe caused to direct their flames upon anydesired part of the die-block.Gas-cocks m m are provided for controlling the flow of gas and soregulating the heat. The gas-burners maybe connected by pipes m with asuitable source of gas-supply, and air may be supplied to said burnersby pipes m The burners are mounted adjustably upon the horizontal rods m"m which in turn are adjustable vertically upon the rods or bolts m. Thegas-jets can thus be arranged to heat any portion of the die-block, sothat the application of the heat to the lead may be varied to equalizethe flow at all points around the circumference of the die-opening. Ifthe leadcovered cable as it emerges from the press tends to curve aroundto one side or the other instead of coming out straight, this means thatthe lead on one side of the die-block is cooler, and consequently harderto work than on the other side. In accordance with my invention,therefore, I direct the flames at a point on the die-block which willsoften the lead to increase its flow on the side of the dieopening wherethe pressure has been diminished. The precise point at which the flamesshould be directed cannot always be stated in advance for everydie-block; but in general the lower part of the die-block or the lead onthe opposite side from the passage through which it enters said chamberrequires to be heated the most. By observing the cable as it comes outthe points at which the lead flowsthe slowest may easily be determinedupon and the heat varied accordingly to equalize the flow.

The principal advantage of my invention is that it enables me to producea perfect lead pipe with a simpler machine and with less expenditure ofpower than heretofore.

I am well aware that gasfiames have heretofore been used to heat thedie-blocks of leadpresses; but they have not been used in the way hereinpointed out for equalizing the flow of lead on all sides of thedie-opening to coinpensate for a dilference in pressure caused by thelack of a bridge.

I claim as my invention- 1. In a lead-press, the combination with adie-block havinga forming-chamber hollowed in the interior thereof, anda die and core-tube meeting in alinement in said chamber to form adie-opening, a single unobstructed passage g being provided in thedie-block through which lead may be forced into the said chamber, saidpassage opening directly upon the body portion of the core at the rearof the dieopening, a raised supporting-tongue h extending along the wallof the forming-chamber at a point directly opposite the opening of saidpassage, said core-tube resting upon and being sustained by said tongueat such point against the pressure of the lead entering theformingchamber through said passage,means for forcing plastic lead intothe forming-chamber through said passage, gas-burners arranged to directtheir flames upon the dieblock, and adjustable mountings for saidburners, whereby the application of the heat to the lead in theforming-chamber maybe varied to compensate for variations in pressure atdifferent parts of said chamber.

2. In a lead-press, the combination with a die-block having aforming-chamber therein and a die and core-tube meeting in alinementtherein to form a die-opening, a single unobstructed passage g beingprovided in the dieblock, opening directly upon thebody portion of thecore-tube at the rear of the die-opening, means for forcing plastic leadthrough said passage into the forming-chamber and so through thedie-opening, and a raised supporting-tongue 7t extending along the Wallof the forming-chamber opposite the mouth of said passage g, thecore-tube resting upon and being sustained by said tongue.

In witness whereof I hereunto subscribe my name this 8th day of January,A. D. 1901.

RODERIC F. HALL.

Witnesses:

DE WITT O. TANNER, GEORGE P. BARTON.

